scholarly journals Function of the Diiron Cluster ofEscherichia coliClass Ia Ribonucleotide Reductase in Proton-Coupled Electron Transfer

2013 ◽  
Vol 135 (23) ◽  
pp. 8585-8593 ◽  
Author(s):  
Bigna Wörsdörfer ◽  
Denise A. Conner ◽  
Kenichi Yokoyama ◽  
Jovan Livada ◽  
Mohammad Seyedsayamdost ◽  
...  
Keyword(s):  
Electron Transfer ◽  
Ribonucleotide Reductase ◽  
Proton Coupled Electron Transfer

Radical Initiation in the Class I Ribonucleotide Reductase: Long-Range Proton-Coupled Electron Transfer?

ChemInform ◽  
2003 ◽  
Vol 34 (32) ◽  
Author(s):  
JoAnne Stubbe ◽  
Daniel G. Nocera ◽  
Cyril S. Yee ◽  
Michelle C. Y. Chang
Keyword(s):  
Electron Transfer ◽  
Long Range ◽  
Ribonucleotide Reductase ◽  
Class I ◽  
Radical Initiation ◽  
Proton Coupled Electron Transfer

Long-range proton-coupled electron transfer in the Escherichia coli class Ia ribonucleotide reductase

2017 ◽  
Vol 61 (2) ◽  
pp. 281-292 ◽  
Author(s):  
Steven Y. Reece ◽  
Mohammad R. Seyedsayamdost
Keyword(s):  
Escherichia Coli ◽  
Electron Transfer ◽  
Amino Acid ◽  
Long Range ◽  
Ribonucleotide Reductase ◽  
Unnatural Amino Acids ◽  
Radical Mechanism ◽  
Tyrosyl Radical ◽  
Proton Coupled Electron Transfer ◽  
Vis Spectroscopy

Escherichia coli class Ia ribonucleotide reductase (RNR) catalyzes the conversion of nucleotides to 2′-deoxynucleotides using a radical mechanism. Each turnover requires radical transfer from an assembled diferric tyrosyl radical (Y•) cofactor to the enzyme active site over 35 Å away. This unprecedented reaction occurs via an amino acid radical hopping pathway spanning two protein subunits. To study the mechanism of radical transport in RNR, a suite of biochemical approaches have been developed, such as site-directed incorporation of unnatural amino acids with altered electronic properties and photochemical generation of radical intermediates. The resulting variant RNRs have been investigated using a variety of time-resolved physical techniques, including transient absorption and stopped-flow UV-Vis spectroscopy, as well as rapid freeze-quench EPR, ENDOR, and PELDOR spectroscopic methods. The data suggest that radical transport occurs via proton-coupled electron transfer (PCET) and that the protein structure has evolved to manage the proton and electron transfer co-ordinates in order to prevent ‘off-pathway’ reactivity and build-up of oxidised intermediates. Thus, precise design and control over the factors that govern PCET is key to enabling reversible and long-range charge transport by amino acid radicals in RNR.

Tyrosine, cysteine, and proton coupled electron transfer in a ribonucleotide reductase-inspired beta hairpin maquette

2019 ◽  
Vol 55 (63) ◽  
pp. 9399-9402 ◽  
Author(s):  
Tyler G. McCaslin ◽  
Cynthia V. Pagba ◽  
Hyea Hwang ◽  
James C. Gumbart ◽  
San-Hui Chi ◽  
...  
Keyword(s):  
Electron Transfer ◽  
Ribonucleotide Reductase ◽  
Transfer Reactions ◽  
Electron Transfer Reactions ◽  
Tyrosine Residues ◽  
Proton Coupled Electron Transfer ◽  
Beta Hairpin

Tyrosine residues act as intermediates in proton coupled electron transfer reactions (PCET) in proteins.

Radical Initiation in the Class I Ribonucleotide Reductase:  Long-Range Proton-Coupled Electron Transfer?

2003 ◽  
Vol 103 (6) ◽  
pp. 2167-2202 ◽  
Author(s):  
JoAnne Stubbe ◽  
Daniel G. Nocera ◽  
Cyril S. Yee ◽  
Michelle C. Y. Chang
Keyword(s):  
Electron Transfer ◽  
Long Range ◽  
Ribonucleotide Reductase ◽  
Class I ◽  
Radical Initiation ◽  
Proton Coupled Electron Transfer
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